This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Congenital bicuspid aortic valve is the most common congenital heart disorder with a prevalence of 1-2% in the general population. These valves often becomes stenotic or regurgitant over time. While it is generally considered a developmental disorder, familial clustering does occur, suggesting that there is genetic predisposition. The goal of this study is to confirm familial clustering of bicuspid aortic valve, and to localize and identify genes responsible for their occurrence.